That would be a question to ask the store directly not here on google. I'm sure they are though.
Call the store. Or take them down, in-person so that the staff can inspect them and give you an answer.
In my experience they are pretty picky. They prefer hard to find editions. Seems to be they want near new condition. Even if you fold pages to keep your place, they might not take it.
Powell's only buys books they are pretty sure they can sell, so you have to ask. Books need to be in good condition with no marking on pages.
Yes. They may direct you to the downtown location though. ..
Powell will buy them if they don't have a thousand of them already. However, one will not get rich selling books to Powell's
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